// Kotlin/Native与Rust的FFI接口实现
// 提供安全、高性能的跨语言互操作机制

#![deny(unsafe_code)]

use std::sync::{Arc, Mutex, RwLock};
use std::ffi::{CStr, CString};
use std::ptr::NonNull;
use std::slice;
use log::{info, warn, error};

// 导入安全的FFI帮助函数
use safe_ffi::{unsafe_cstr_to_string, unsafe_copy_c_string, unsafe_c_string_length, unsafe_compare_c_strings,
               unsafe_read_u8, unsafe_write_u8, unsafe_read_u16_le, unsafe_write_u16_le,
               unsafe_read_u32_le, unsafe_write_u32_le, unsafe_read_u64_le, unsafe_write_u64_le,
               unsafe_set_ptr_value, unsafe_copy_memory_block, unsafe_get_cstr_ref};

// 导入核心类型
use super::{Capability, CapabilityId};
use super::kuikly_service::{KuiklyUIService, KuiklyError};
use serde::{Serialize, Deserialize};

// 全局Kuikly服务实例
lazy_static::lazy_static! {
    static ref GLOBAL_KOTLIN_INTEROP_SERVICE: RwLock<Option<Arc<KuiklyUIService>>> = RwLock::new(None);
}

// 初始化Kotlin/Native互操作服务
#[no_mangle]
pub extern "C" fn zenrs_kotlin_interop_init() -> bool {
    // 这里应该从系统中获取Kuikly服务实例
    // 为了简化示例，我们返回true表示初始化成功
    info!("Kotlin/Native interop service initialized");
    true
}

// 设置全局Kuikly服务实例（由其他模块调用）
pub fn set_global_kuikly_service(service: Arc<KuiklyUIService>) {
    let mut global_service = GLOBAL_KOTLIN_INTEROP_SERVICE.write().unwrap();
    *global_service = Some(service);
}

// 获取Kuikly服务实例的辅助方法
fn get_kuikly_service() -> Result<Arc<KuiklyUIService>, KuiklyError> {
    let global_service = GLOBAL_KOTLIN_INTEROP_SERVICE.read().unwrap();
    if let Some(service) = global_service.as_ref() {
        Ok(Arc::clone(service))
    } else {
        Err(KuiklyError::ExokernelError)
    }
}

// 消息处理结果枚举
#[repr(C)]
pub enum KotlinInteropResult {
    Success = 0,
    Failure = 1,
    InvalidParameter = 2,
    OutOfMemory = 3,
    NotInitialized = 4,
    ServiceUnavailable = 5,
}

// UI事件数据结构
#[repr(C)]
pub struct KotlinUIEvent {
    event_type: u32,
    x: i32,
    y: i32,
    button_state: u32,
    key_code: u32,
    modifier_state: u32,
    timestamp: u64,
}

// UI命令数据结构
#[repr(C)]
pub struct KotlinUICommand {
    command_id: u32,
    target_id: u64,
    data_size: u32,
    data_ptr: *const u8,
}

// 发送UI命令到Kuikly服务
#[no_mangle]
pub extern "C" fn zenrs_send_ui_command(
    command: *const KotlinUICommand,
    result_code: *mut i32
) -> bool {
    if command.is_null() || result_code.is_null() {
        unsafe { *result_code = KotlinInteropResult::InvalidParameter as i32; }
        return false;
    }

    let cmd = unsafe { &*command };
    let data_slice = unsafe {
        if cmd.data_size > 0 && !cmd.data_ptr.is_null() {
            Some(slice::from_raw_parts(cmd.data_ptr, cmd.data_size as usize))
        } else {
            None
        }
    };

    // 这里应该实现实际的命令发送逻辑
    info!("Received UI command: {}, target_id: {}, data_size: {}", 
          cmd.command_id, cmd.target_id, cmd.data_size);

    // 模拟发送命令
    unsafe {
        unsafe_set_ptr_value(result_code, KotlinInteropResult::Success as i32);
    }
    true
}

// 注册UI事件回调函数
#[no_mangle]
pub extern "C" fn zenrs_register_ui_event_callback(
    callback: extern "C" fn(*const KotlinUIEvent),
    user_data: *mut std::ffi::c_void
) -> bool {
    // 这里应该实现实际的回调注册逻辑
    info!("UI event callback registered");
    true
}

// 获取系统信息
#[no_mangle]
pub extern "C" fn zenrs_get_system_info(
    buffer: *mut u8,
    buffer_size: u32,
    actual_size: *mut u32
) -> bool {
    if buffer.is_null() || actual_size.is_null() {
        return false;
    }

    // 准备系统信息
    let system_info = json!({
        "name": "ZENrs",
        "version": "1.0.0",
        "architecture": "exokernel",
        "ui_framework": "Kuikly",
        "services": ["kuikly", "fs", "ipc"]
    });

    let system_info_str = system_info.to_string();
    let system_info_bytes = system_info_str.as_bytes();
    let required_size = system_info_bytes.len() as u32;

    unsafe {
        unsafe_set_ptr_value(actual_size, required_size);
    }

    // 检查缓冲区大小是否足够
    if buffer_size >= required_size {
        unsafe {
            unsafe_copy_memory_block(system_info_bytes.as_ptr(), buffer, system_info_bytes.len());
        }
        true
    } else {
        false
    }
}

// 分配内存（供Kotlin/Native使用）
#[no_mangle]
pub extern "C" fn zenrs_allocate_memory(size: u64, out_ptr: *mut *mut std::ffi::c_void) -> bool {
    if out_ptr.is_null() || size == 0 {
        return false;
    }

    // 分配内存
    let mut vec = Vec::with_capacity(size as usize);
    let ptr = vec.as_mut_ptr();
    std::mem::forget(vec); // 防止释放内存

    unsafe {
        unsafe_set_ptr_value(out_ptr, ptr as *mut std::ffi::c_void);
    }
    true
}

// 释放内存（供Kotlin/Native使用）
#[no_mangle]
pub extern "C" fn zenrs_free_memory(ptr: *mut std::ffi::c_void) -> bool {
    if ptr.is_null() {
        return true;
    }

    // 这里简化处理，实际应用中应该跟踪分配的内存块
    // 在生产环境中，应该实现一个内存跟踪系统
    true
}

// 创建共享内存区域
#[no_mangle]
pub extern "C" fn zenrs_create_shared_memory(
    size: u64,
    name: *const i8,
    out_handle: *mut u64
) -> bool {
    if out_handle.is_null() || size == 0 {
        return false;
    }

    // 转换C字符串为Rust字符串
    let name_str = if !name.is_null() {
        unsafe {
            match unsafe_get_cstr_ref(name).to_str() {
                Ok(s) => Some(s.to_string()),
                Err(_) => None,
            }
        }
    } else {
        None
    };

    info!("Creating shared memory: size={}, name={:?}", 
          size, name_str);

    // 模拟创建共享内存
    unsafe {
        unsafe_set_ptr_value(out_handle, 123456);
    }
    true
}

// 打开共享内存区域
#[no_mangle]
pub extern "C" fn zenrs_open_shared_memory(
    handle: u64,
    out_ptr: *mut *mut std::ffi::c_void,
    out_size: *mut u64
) -> bool {
    if out_ptr.is_null() || out_size.is_null() {
        return false;
    }

    // 模拟打开共享内存
    info!("Opening shared memory with handle: {}", handle);

    unsafe {
        unsafe_set_ptr_value(out_ptr, std::ptr::null_mut());
        unsafe_set_ptr_value(out_size, 0);
    }
    true
}

// 关闭共享内存区域
#[no_mangle]
pub extern "C" fn zenrs_close_shared_memory(handle: u64) -> bool {
    info!("Closing shared memory with handle: {}", handle);
    true
}

// 发送自定义消息
#[no_mangle]
pub extern "C" fn zenrs_send_custom_message(
    target_id: u64,
    message_type: u32,
    data: *const u8,
    data_size: u32
) -> bool {
    info!("Sending custom message: type={}, target_id={}, data_size={}", 
          message_type, target_id, data_size);

    // 这里应该实现实际的消息发送逻辑
    true
}

// 获取应用列表
#[no_mangle]
pub extern "C" fn zenrs_get_application_list(
    buffer: *mut u8,
    buffer_size: u32,
    actual_size: *mut u32
) -> bool {
    // 模拟获取应用列表
    let apps = json!([
        {"id": 1, "name": "电话", "icon": "phone.png", "running": true},
        {"id": 2, "name": "信息", "icon": "message.png", "running": true},
        {"id": 3, "name": "相机", "icon": "camera.png", "running": false},
        {"id": 4, "name": "浏览器", "icon": "browser.png", "running": true},
        {"id": 5, "name": "音乐", "icon": "music.png", "running": false}
    ]);

    let apps_str = apps.to_string();
    let apps_bytes = apps_str.as_bytes();
    let required_size = apps_bytes.len() as u32;

    unsafe {
        unsafe_set_ptr_value(actual_size, required_size);
    }

    if buffer_size >= required_size && !buffer.is_null() {
        unsafe {
            unsafe_copy_memory_block(apps_bytes.as_ptr(), buffer, apps_bytes.len());
        }
        true
    } else {
        false
    }
}

// 启动应用
#[no_mangle]
pub extern "C" fn zenrs_launch_application(app_id: u64, result_code: *mut i32) -> bool {
    info!("Launching application with ID: {}", app_id);
    unsafe {
        unsafe_set_ptr_value(result_code, KotlinInteropResult::Success as i32);
    }
    true
}

// 关闭应用
#[no_mangle]
pub extern "C" fn zenrs_close_application(app_id: u64, result_code: *mut i32) -> bool {
    info!("Closing application with ID: {}", app_id);
    unsafe {
        unsafe_set_ptr_value(result_code, KotlinInteropResult::Success as i32);
    }
    true
}